naasifsalie

I have a 1999 A4 1.8T. Recently the turbo stopped boosting. It started with a lack of power. The car would drive and make a funny sound from the turbo. Then the noise got worse and worse. I replaced the turbo and the car drove fine for about 100meters. It then jerked a bit and now does exactly the same thing. No power. Funny sound from Turbo while driving....not a constant sound, comes and goes. Sounds like air spinning the turbo but no power! What could be causing this? Oil Blockage? CAT Blockage? Diverter Valve? Waste Gate? Butterfly control????

G_claudz

Check your hoses from the turbo, mine had a large boost leak and had the same symptoms you are talking about

Prospeeder

Yea sounds like you didnt tighten a clamp and a boost hose blew off.

ECS Tuning-Audi

Check your vac lines. Especially the ones near the N75 valve which controls your waste gate flapper.

The suction pump is another spot 1.8Ts like to bleed boost. Looks like the image below.